POWER LOSS (W) LTC3406B-1.2 1.5MHz, 600mA Synchronous Step-Down Regulator in ThinSOT FEATURES DESCRIPTIO High Efficiency: Up to 96% The LTC 3406B-1.2 is a high efficiency monolithic syn- 600mA Output Current at V = 3V chronous buck regulator using a constant frequency, IN 2.5V to 5.5V Input Voltage Range current mode architecture. Supply current with no load is 1.5MHz Constant Frequency Operation 300A dropping to <1A in shutdown. The 2.5V to 5.5V No Schottky Diode Required input voltage range makes the LTC3406B-1.2 ideally suited Low Quiescent Current: 300A for single Li-Ion battery-powered applications. 100% duty Shutdown Mode Draws < 1A Supply Current cycle provides low dropout operation, extending battery Current Mode Operation for Excellent Line and life in portable systems. PWM pulse skipping mode opera- Load Transient Response tion provides very low output ripple voltage for noise Overtemperature Protected sensitive applications. TM Low Profile (1mm) ThinSOT Package Switching frequency is internally set at 1.5MHz, allowing the use of small surface mount inductors and capacitors. U The internal synchronous switch increases efficiency and APPLICATIO S eliminates the need for an external Schottky diode. The Cellular Telephones LTC3406B-1.2 is available in a low profile (1mm) ThinSOT Personal Information Appliances package. Wireless and DSL Modems , LTC and LT are registered trademarks of Linear Technology Corporation. All other trademarks are the property of their respective owners. ThinSOT is a trademark of Linear Digital Still Cameras Technology Corporation. Protected by U.S. Patents including 5481178, 6580258, 6304066, MP3 Players 6127815, 6498466, 6611131. Portable Instruments TYPICAL APPLICATIO Efficiency and Power Loss 100 1 High Efficiency Step-Down Converter 90 2.2H V V EFFICIENCY IN 80 V SW OUT IN 0.1 2.7V TO 5.5V C 1.2V C OUT IN 10F 600mA 70 4.7F LTC3406B-1.2 CER CER 60 0.01 RUN V OUT 3406B12 TA01a 50 GND POWER LOSS 40 0.001 30 V = 2.7V IN 20 V = 3.6V IN V = 4.2V IN 10 0.0001 0.1 1 10 100 1000 LOAD CURRENT (mA) 3406B12 TA01b sn3406b12 3406b12fs 1 EFFICIENCY (%) U ULTC3406B-1.2 UUW ABSOLUTE AXI U RATI GS PACKAGE/ORDER I FOR ATIO (Note 1) Input Supply Voltage .................................. 0.3V to 6V ORDER PART TOP VIEW RUN, V Voltages................................... 0.3V to V NUMBER OUT IN SW Voltage (DC) ......................... 0.3V to (V + 0.3V) RUN 1 5 V IN OUT LTC3406BES5-1.2 P-Channel Switch Source Current (DC) ............. 800mA GND 2 SW 3 4 V N-Channel Switch Sink Current (DC) ................. 800mA IN Peak SW Sink and Source Current (V = 3V)........ 1.3A S5 PART MARKING S5 PACKAGE IN 5-LEAD PLASTIC TSOT-23 Operating Temperature Range (Note 2) .. 40C to 85C T = 125C, = 250C/ W, = 90C/ W LTBMR JMAX JA JC Junction Temperature (Notes 3, 5) ...................... 125C Storage Temperature Range ................ 65C to 150C Consult LTC Marketing for parts specified with wider operating temperature ranges. Lead Temperature (Soldering, 10 sec)................. 300C ELECTRICAL CHARACTERISTICS The denotes specifications which apply over the full operating temperature range, otherwise specifications are T = 25C. V = 3.6V unless otherwise specified. A IN SYMBOL PARAMETER CONDITIONS MIN TYP MAX UNITS V Regulated Output Voltage 1.164 1.2 1.236 V OUT V Output Overvoltage Lockout V = V V 2.5 6.25 10 % OVL OVL OVL OUT V Output Voltage Line Regulation V = 2.5V to 5.5V 0.04 0.4 %/V OUT IN I Peak Inductor Current V = 3V, V = 1.08V, Duty Cycle < 35% 0.75 1 1.25 A PK IN OUT V Output Voltage Load Regulation 0.5 % LOADREG V Input Voltage Range 2.5 5.5 V IN I Input DC Bias Current (Note 4) S = 1.08V 300 400 A V OUT Shutdown V = 0V, V = 5.5V 0.1 1 A RUN IN f Oscillator Frequency V = 1.2V 1.2 1.5 1.8 MHz OSC OUT V = 0V 210 kHz OUT R R of P-Channel FET I = 100mA 0.4 0.5 PFET DS(ON) SW R R of N-Channel FET I = 100mA 0.35 0.45 NFET DS(ON) SW I SW Leakage V = 0V, V = 0V or 5V, V = 5V 0.01 1 A LSW RUN SW IN V RUN Threshold 0.3 1 1.5 V RUN I RUN Leakage Current 0.01 1 A RUN sn3406b12 3406b12fs 2 U WWW